Vibration-absorbing structure for golf club shaft

ABSTRACT

A golf club shaft includes a shaft having a tubular wall delimiting an interior space. The shaft includes a first end coupled with a head and a second end coupled with a grip. A light vibration-absorbing member is mounted in the interior space of the shaft. At least a portion of the light vibration-absorbing member is in contact with the tubular wall for absorbing vibration that results from striking a golf ball and that is transmitted from the head to the shaft.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a vibration-absorbing structure. In particular, the present invention relates to a vibration-absorbing structure for a golf club shaft.

2. Description of Related Art

FIG. 1 of the drawings illustrates a conventional golf club comprising a shaft 10, a head 20, and a grip 30. The shaft 10 is substantially an elongated tubular member with the head 20 coupled to an end thereof and with the grip 30 coupled to the other end thereof. The shaft 10 is made of a material having a high coefficient of restitution. For example, the shaft 10 can be formed by a plurality of windings made of carbon fiber prepreg, graphite fiber prepreg, or fiberglass. Thus, the shaft 10 is highly flexible. The head 20 is used to strike a golf ball and the grip 30 allows firm grip by the golfer. Such a golf club head is disclosed in, e.g., U.S. Pat. Nos. 3,313,541; 4,023,801; 4,135,035; and 5,437,450.

When striking a golf ball, vibration is transmitted upward from the head 20 through the shaft 10 to the grip 30. Each of the head 20, the shaft 10, and the grip 30 absorb a portion of the vibration. However, the vibration could not be completely absorbed, and the unabsorbed vibration is transmitted to the golfer's hands. The hands of a golfer that plays for a long time might feel uncomfortable or numb. The striking accuracy is thus adversely affected. The hands of the golfer might even be injured.

OBJECTS OF THE INVENTION

An object of the present invention is to provide a vibration-absorbing structure for a golf club shaft that provides improved vibration-absorbing effect.

Another object of the present invention is to provide a vibration-absorbing structure for a golf club shaft that provides increased gripping comfort.

SUMMARY OF THE INVENTION

A golf club shaft in accordance with an aspect of the present invention comprises a shaft including a tubular wall delimiting an interior space. The shaft includes a first end coupled with a head and a second end coupled with a grip. A light vibration-absorbing member is mounted in the interior space of the shaft. At least a portion of the light vibration-absorbing member is in contact with the tubular wall for absorbing vibration that results from striking a golf ball and that is transmitted from the head to the shaft.

The light vibration-absorbing member may be made of foaming synthetic resin. In an embodiment, the light vibration-absorbing member is made of a material selected from a group consisting of rubber, thermoplastic elastomer, polyurethane, nylon, polypropylene, acrylonitrile-butadiene-styrene, polyethylene terephthalate, vinyl chloride, and high molecular vibration-absorbing material. Alternatively, the light vibration-absorbing member is integrally formed in the whole interior space of the shaft by injection molding.

Preferably, the light vibration-absorbing member fills the whole interior space of the shaft.

The light vibration-absorbing member may include a hollow portion. Another light vibration-absorbing member may be mounted in the hollow portion and made of a material different from that of the light vibration-absorbing member, providing different damping coefficients for obtaining a composite vibration-absorbing effect. Alternatively, the another light vibration-absorbing member and the light vibration-absorbing member are made of the same material yet filled in the interior space in different compactnesses, providing different damping coefficients for obtaining a composite vibration-absorbing effect. A plurality of protrusions or recessed portions may be formed on an inner periphery of the hollow portion for distributing the vibration. Alternatively, the hollow portion includes a wavy or threaded inner periphery for distributing the vibration.

In another embodiment, the light vibration-absorbing member includes a plurality of protruded sections in contact with the tubular wall and a plurality of recessed buffering sections not in contact with the tubular wall. The protruded sections and the recessed buffering sections are alternatively disposed, providing a multi-stage vibration-absorbing effect.

In a further embodiment, the light vibration-absorbing member is a pre-formed column inserted into the interior space of the shaft and fixed to the tubular wall by adhesive. Preferably, the column is adjacent to the head.

In still another embodiment, the shaft includes a plurality of columns of light vibration-absorbing members mounted in the interior space, providing different damping coefficients for obtaining a composite vibration-absorbing effect. The columns may be made of different materials or of the same material yet filled in the interior space in different compactnesses.

In yet another embodiment, two of the columns adjacent to each other are spaced by a spacer, providing a multi-stage vibration-absorbing effect.

A golf club shaft in accordance with another aspect of the present invention comprises a shaft including a tubular wall delimiting an interior space. A plurality of light vibration-absorbing members are mounted in the interior space of the shaft. The light vibration-absorbing members absorb vibration that results from striking a golf ball and that is transmitted from a head coupled to an end of the shaft to the shaft.

In an embodiment, the light vibration-absorbing members are spaced from one another.

In another embodiment, the light vibration-absorbing members are in contact with one another.

Preferably, the light vibration-absorbing members are fixed in the interior space by adhesive.

In a further embodiment, at least one the light vibration-absorbing members includes a hollow portion.

In still another embodiment, a plurality of protrusions are formed on an inner periphery of the hollow portion for distributing the vibration.

In yet another embodiment, the hollow portion includes a wavy inner periphery for distributing the vibration.

In still another embodiment, the hollow portion includes a threaded inner periphery for distributing the vibration.

Other objects, advantages and novel features of this invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view, partly sectioned, of a conventional golf club;

FIG. 2 is a perspective view, partly sectioned, of an embodiment of a golf club in accordance with the present invention;

FIG. 3 is a sectional view of a shaft of the golf club in FIG. 2;

FIG. 4 is a sectional view of a modified embodiment of the shaft of the golf club in accordance with the present invention;

FIG. 5 is a sectional view of another modified embodiment of the shaft of the golf club in accordance with the present invention;

FIG. 6 is a sectional view of a further modified embodiment of the shaft of the golf club in accordance with the present invention;

FIG. 7 is a sectional view of still another modified embodiment of the shaft of the golf club in accordance with the present invention;

FIG. 8 is a sectional view of yet another modified embodiment of the shaft of the golf club in accordance with the present invention;

FIG. 9 is a sectional view of still another modified embodiment of the shaft of the golf club in accordance with the present invention;

FIG. 10 is a sectional view of yet another modified embodiment of the shaft of the golf club in accordance with the present invention;

FIG. 11 is a sectional view of still another modified embodiment of the shaft of the golf club in accordance with the present invention;

FIG. 12 is a sectional view of yet another modified embodiment of the shaft of the golf club in accordance with the present invention; and

FIG. 13 is a sectional view of still another modified embodiment of the shaft of the golf club in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 2 and 3, a golf club in accordance with the present invention comprises a shaft 10, a head 20, a grip 30, and a light vibration-absorbing member 40. The shaft 10 is an elongated tubular member with the head 20 coupled to an end thereof and with the grip 30 coupled to the other end thereof. The shaft 10 includes a tubular wall 11 delimiting an interior space 12.

The shaft 10 is made of a material having a high coefficient of restitution so as to be highly flexible. In an example, the shaft 10 is formed by a plurality of windings of carbon fiber prepreg. Alternatively, the shaft 10 is integrally formed by metal or alloy. The light vibration-absorbing member 40 is received in the interior space 12 of the shaft 10. The head 20 is of an iron club type, wooden club type, or putter type. The head 20 is used to strike a golf ball. The grip 30 is made of an elastomeric material such as rubber, allowing a golfer to grip for swinging or putting purposes.

Still referring to FIGS. 2 and 3, the light vibration-absorbing member 40 may be made of foaming synthetic resin or other resin material such as rubber, thermoplastic elastomer, polyurethane (PU), nylon, polypropylene, acrylonitrile-butadiene-styrene (ABS), polyethylene terephthalate (PET), vinyl chloride or other high molecular vibration-absorbing material. Preferably, the light vibration-absorbing member 40 is integrally formed in the whole interior space 12 of the shaft 10 by injection molding.

Still referring to FIGS. 2 and 3, when striking a golf ball with the golf club in accordance with the present invention, vibration is generated while the golf ball is stricken by the head 20 and the vibration is transmitted upward through the shaft 10. A portion of the upwardly transmitted vibration is absorbed by the head 20 and the tubular wall 11 of the shaft 10, and the remaining portion of the upwardly transmitted vibration is absorbed by the light vibration-absorbing member 40. Thus, transmission of the vibration to the grip 30 is effectively avoided. Uncomfortable feeling or numbness of the golfer's hands holding the grip 30 is less likely to occur, even after long-term playing. Striking accuracy is assured and the risk of injury to the golfer's hands is reduced.

FIG. 4 illustrates another embodiment of the shaft 10, wherein the light vibration-absorbing member 40 includes a hollow portion 41, allowing adjustment of the vibration-absorbing capacity.

FIG. 5 illustrates a further embodiment of the shaft 10, wherein another light vibration-absorbing member 40′ is be received in the hollow portion 41. The light vibration-absorbing members 40 and 40′ may be made of different materials or of the same material yet filled in the interior space 12 in different compactnesses to provide different damping coefficients, thereby providing a composite vibration-absorbing effect.

FIG. 6 illustrates still another embodiment of the shaft 10, wherein an inner periphery of the hollow portion 41 of the light vibration-absorbing member 40 includes a plurality of protrusions 411 or recessed portions (not shown) for improving the vibration-absorbing effect by further distributing the vibration generated as a result of striking a golf ball.

FIG. 7 illustrates still another modified embodiment of the shaft 10, wherein the inner periphery of the hollow portion 41′ is wavy or threaded for improving the vibration-absorbing effect by further distributing the vibration generated as a result of striking a golf ball.

FIG. 8 illustrates yet another modified embodiment of the shaft 10, wherein the light vibration-absorbing member 40 includes a plurality of protruded sections 42 in contact with the tubular wall 11 and a plurality of recessed buffering sections 43 not in contact with the tubular wall 11. Preferably, the protruded sections 42 and the recessed buffering sections 43 are alternatively disposed, providing a multi-stage vibration-absorbing effect.

FIG. 9 is a sectional view of still another modified embodiment of the shaft 10, wherein the light vibration-absorbing member 40 is a pre-formed column inserted into the interior space 12 of the shaft 10 and fixed in place by adhesive. Preferably, the column (i.e., the light vibration-absorbing member 40) is located adjacent to the head 20 for instantly absorbing the vibration at the beginning of the vibration.

FIG. 10 is a sectional view of yet another modified embodiment of the shaft 10, wherein a plurality of columns of light vibration-absorbing members 40 c, 40 b, 40 a, 40 b, and 40 c are mounted in the shaft 10 and stacked one another in sequence. Preferably, the light vibration-absorbing members 40 a, 40 b, 40 c, are made of different materials or of the same material yet filled in the interior space 12 in different compactnesses to provide different damping coefficients, thereby providing a composite vibration-absorbing effect. Preferably, the damping coefficients of the light vibration-absorbing members 40 c, 40 b, 40 a, 40 b, and 40 c are low, medium, high, medium, and low in sequence (or high, medium, low, medium, and high in sequence). A composite vibration-absorbing effect is thus obtained.

FIG. 11 is a sectional view of still another modified embodiment of the shaft 10, wherein a plurality of columns of light vibration-absorbing members 40 a, 40 b, 40 c, 40 d, and 40 e are mounted in the shaft 10 and stacked one upon the other in sequence. Preferably, the light vibration-absorbing members 40 a, 40 b, 40 c, 40 d, and 40 e are made of different materials or of the same material yet filled in the interior space 12 in different compactnesses to provide different damping coefficients, thereby providing a composite vibration-absorbing effect. Preferably, the damping coefficient of an upper one of the light vibration-absorbing members 40 a, 40 b, 40 c, 40 d, and 40 e is higher (or lower) than that of a lower one of the light vibration-absorbing members 40 a, 40 b, 40 c, 40 d, and 40 e. A composite vibration-absorbing effect is thus obtained.

FIG. 12 is a sectional view of yet another modified embodiment of the shaft 10, wherein a plurality of light vibration-absorbing members 40 a, 40 b, and 40 c are mounted in the shaft 10 and spaced from one another along a longitudinal direction of the shaft 10. Preferably, the light vibration-absorbing members 40 a, 40 b, and 40 c are made of different materials or of the same material yet filled in the interior space 12 in different compactnesses to provide different damping coefficients, thereby providing a composite vibration-absorbing effect. Preferably, the light vibration-absorbing members 40 a, 40 b, and 40 c are fixed in the interior space 12 of the shaft 10 by adhesive.

FIG. 13 is a sectional view of still another modified embodiment of the shaft 10, wherein a plurality of light vibration-absorbing members 40 are mounted in the shaft 10 and spaced from one another along a longitudinal direction of the shaft 10 by a spacer 50, providing a multi-stage vibration-absorbing effect. Preferably, the light vibration-absorbing members 40 are made of different materials or of the same material yet filled in the interior space 12 in different compactnesses to provide different damping coefficients, thereby providing a composite vibration-absorbing effect. Preferably, the light vibration-absorbing members 40 a, 40 b, and 40 c are bonded in the interior space 12 of the shaft 10 by adhesive.

The structures shown in FIGS. 4 through 8 can be incorporated into the embodiment of FIG. 13. For example, at least one of the light vibration-absorbing members 40 may include a hollow portion 41. Further, at least one of the light vibration-absorbing members 40 may include a hollow portion 41 in which a different light vibration-absorbing member 40′ is mounted. At least one of the light vibration-absorbing members 40 may include a hollow portion 41 having a plurality of protrusions 411 on an inner periphery thereof. The vibration-absorbing effect can be further improved.

While the principles of this invention have been disclosed in connection with specific embodiments, it should be understood by those skilled in the art that these descriptions are not intended to limit the scope of the invention, and that any modification and variation without departing the spirit of the invention is intended to be covered by the scope of this invention defined only by the appended claims. 

1. A golf club shaft with a vibration-absorbing structure, comprising: a shaft including a tubular wall delimiting an interior space, the shaft including a first end adapted to be coupled with a head and a second end adapted to be coupled with a grip; and a light vibration-absorbing member mounted in the interior space of the shaft, at least a portion of the light vibration-absorbing member being in contact with the tubular wall for absorbing vibration that results from striking a golf ball and that is transmitted from the head to the shaft.
 2. The golf club shaft with a vibration-absorbing structure as claimed in claim 1, wherein the light vibration-absorbing member is made of foaming synthetic resin.
 3. The golf club shaft with a vibration-absorbing structure as claimed in claim 1, wherein the light vibration-absorbing member is made of a material selected from a group consisting of rubber, thermoplastic elastomer, polyurethane, nylon, polypropylene, acrylonitrile-butadiene-styrene, polyethylene terephthalate, vinyl chloride, and high molecular vibration-absorbing material.
 4. The golf club shaft with a vibration-absorbing structure as claimed in claim 1, wherein the light vibration-absorbing member is integrally formed in the whole interior space of the shaft by injection molding.
 5. The golf club shaft with a vibration-absorbing structure as claimed in claim 1, wherein the light vibration-absorbing member fills the whole interior space of the shaft.
 6. The golf club shaft with a vibration-absorbing structure as claimed in claim 1, wherein the light vibration-absorbing member includes a hollow portion.
 7. The golf club shaft with a vibration-absorbing structure as claimed in claim 6, further including another light vibration-absorbing member mounted in the hollow portion, said another light vibration-absorbing member being made of a material different from that of the light vibration-absorbing member, providing different damping coefficients for obtaining a composite vibration-absorbing effect.
 8. The golf club shaft with a vibration-absorbing structure as claimed in claim 6, further including another light vibration-absorbing member mounted in the hollow portion, said another light vibration-absorbing member and the light vibration-absorbing member being made of the same material yet filled in the interior space in different compactnesses, providing different damping coefficients for obtaining a composite vibration-absorbing effect.
 9. The golf club shaft with a vibration-absorbing structure as claimed in claim 6, further including a plurality of protrusions on an inner periphery of the hollow portion for distributing the vibration.
 10. The golf club shaft with a vibration-absorbing structure as claimed in claim 6, further including a plurality of recessed portions on an inner periphery of the hollow portion for distributing the vibration.
 11. The golf club shaft with a vibration-absorbing structure as claimed in claim 6, wherein the hollow portion includes a wavy or threaded inner periphery for distributing the vibration.
 12. The golf club shaft with a vibration-absorbing structure as claimed in claim 1, wherein the light vibration-absorbing member includes a plurality of protruded sections in contact with the tubular wall and a plurality of recessed buffering sections not in contact with the tubular wall, and wherein the protruded sections and the recessed buffering sections are alternatively disposed, providing a multi-stage vibration-absorbing effect.
 13. The golf club shaft with a vibration-absorbing structure as claimed in claim 1, wherein the light vibration-absorbing member is a pre-formed column inserted into the interior space of the shaft and fixed to the tubular wall by adhesive.
 14. The golf club shaft with a vibration-absorbing structure as claimed in claim 13, wherein the column is adjacent to the head.
 15. The golf club shaft with a vibration-absorbing structure as claimed in claim 13, wherein the shaft includes a plurality of columns of light vibration-absorbing members mounted in the interior space, providing different damping coefficients for obtaining a composite vibration-absorbing effect.
 16. The golf club shaft with a vibration-absorbing structure as claimed in claim 15, wherein the columns are made of different materials.
 17. The golf club shaft with a vibration-absorbing structure as claimed in claim 15, wherein the columns are made of the same material yet filled in the interior space in different compactnesses.
 18. The golf club shaft with a vibration-absorbing structure as claimed in claim 15, wherein two of the columns adjacent to each other are spaced by a spacer, providing a multi-stage vibration-absorbing effect.
 19. A golf club shaft with a vibration-absorbing structure, comprising: a shaft including a tubular wall delimiting an interior space; and a plurality of light vibration-absorbing members mounted in the interior space of the shaft, the light vibration-absorbing members absorbing vibration that results from striking a golf ball and that is transmitted from a head coupled to an end of the shaft to the shaft.
 20. The golf club shaft with a vibration-absorbing structure as claimed in claim 19, wherein the light vibration-absorbing members are spaced from one another.
 21. The golf club shaft with a vibration-absorbing structure as claimed in claim 19, wherein the light vibration-absorbing members are in contact with one another.
 22. The golf club shaft with a vibration-absorbing structure as claimed in claim 19, wherein the light vibration-absorbing members are fixed in the interior space by adhesive.
 23. The golf club shaft with a vibration-absorbing structure as claimed in claim 19, wherein at least one the light vibration-absorbing members includes a hollow portion.
 24. The golf club shaft with a vibration-absorbing structure as claimed in claim 23, further including a plurality of protrusions formed on an inner periphery of the hollow portion for distributing the vibration.
 25. The golf club shaft with a vibration-absorbing structure as claimed in claim 23, wherein the hollow portion includes a wavy inner periphery for distributing the vibration.
 26. The golf club shaft with a vibration-absorbing structure as claimed in claim 23, wherein the hollow portion includes a threaded inner periphery for distributing the vibration. 